For this dish you need those wonderful Italian artichokes, not too big, but with spines on top (they are tastier), which come from Puglia, Sicily or Sardinia. The tenderest ones will have a small choke inside and are delicious to eat whole when the outer leaves and the tops have been discarded.
To desalt the capers, soak them in a bowl of cold water for 15 minutes, then drain well before using.